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Название форумаСвободная площадка
Название темыRE: ИЗВЕСТНЯК ЯЗЫКОМ
URL темыhttps://chronologia.org/dc/dcboard.php?az=show_topic&forum=264&topic_id=51636&mesg_id=51807
51807, RE: ИЗВЕСТНЯК ЯЗЫКОМ
Послано jey, 08-02-2008 13:18
Кроме как в книгу никуда и не слазишь.;-) Отсканю фотографии техпроцесса, запощу. Пока можете автора почитать (правда пишет он таким языком, что я на третьем предложении начинаю бороться со сном ):+

Manufacturing a limestone barrel-shaped vase

The experimental vase was carved to shape from a rough block of soft limestone with large and small copper adzes, flat and crosscut copper chisels, a mallet, flint chisels, punches and scrapers and sandstone rubbers. No set measurements were adhered to, the shape of the vase being achieved by acting upon intuitive judgements. The shoulders of a barrel-shaped vase are wider than its flat bottom; it made sense to align the narrower base surface directly under the centre of the projected top surface, and ensure parallelism between them. The top and the bottom surfaces were finished before any further shaping took place.
The initial shaping of the curved sides now commenced . Copper adzes were utilized to pare away the limestone from the top to the bottom. However, a hand-held, adze-shaped flint blade could also have been employed for this operation: if this vessel had been manufactured from granite or porphyry, flint chisels and punches would have been used to chip away the stone. During this shaping, constant checking of the relationship between the top and the bottom surfaces to the curved sides became necessary. The second phase of the barrel form could now begin. Using small copper chisels, a mallet, and flint scrapers of different shapes and sizes, allowed the shoulders and neck gradually to be carved into shape . After checking the final form of the vase, sandstone rubbers of graded textures were used to smooth the whole of its surface. The final smoothing, however, was deferred until the completion of the hollowing. The vase measured 10 cm in diameter, 10.7 cm in height, with a neck diameter and height of 7.5 cm and 1 cm respectively .
The first stage of hollowing commenced with a tubular drill, initially part-way into the vase. It was decided to tubular drill it, even though soft limestone was probably hollowed with crescent borers in ancient times. This method appeared to be the safest way for a beginner to practise the hollowing tasks. In Chapter 4, an unprovenanced and uncatalogued calcite vessel in the Petrie Collection was mentioned; this vessel has a circular groove upon its top surface. The groove is likely to have been made in order to locate a tubular drill, which prevented the tube from 'wandering' around the surface. The experimental vase was similarly prepared . First, the drill-tube was correctly positioned, so that a mark could be made around its circumference, which allowed a groove to be chipped out with a flint chisel and mallet, just inside the circular mark. In fact, two grooves were so prepared, one within the other, in order that two different diameter tubes could be used for the drilling.
There is evidence that different diameter tubular drills, rotated upon the same axis, were utilized on stone in ancient times. In the Petrie Collection is a tubular-shaped basalt core; horizontal striations are in evidence on its internal and external surfaces. The core's date and provenance are unknown. The core does not taper at all; its internal and external sides are perfectly parallel. Petrie ventured an opinion that the core came from an enlarged hole in basalt; a lesser hole had been cut and found too small, and then a larger hole was made, detaching a tube of basalt. A different interpretation may be presented to explain its shape. Possibly, the lesser hole, after the removal of the solid core left by the smaller tubular drill, was deliberately enlarged, reducing the risk of breaking a vessel by trying to remove a larger, solid core . The use of this technology in the experimental vase showed that the tubular-shaped core breaks upon removal; soft stone is liable to fracture easily. But hard stone, such as basalt, may occasion­ally have survived removal intact. Both ends of the Petrie Collection basalt tube are flat. One might have expected the tube to possess a jagged end, where it was broken out from the hole. Nevertheless, there are solid cores in the Petrie Collection which have flattened and polished ends, although the purpose for this is unclear. However, the tubular core could have been drilled through the top part of a vase being manufactured in two pieces; this would account for each end being flat.
There is other evidence for the use of different diameter tubular drills upon the same axis. Petrie mentions a marble eye for inlaying, made with two tube drill-holes, one within the other, showing the thickness of the small drills. This technique was probably used regularly by Egyptian workers for stone vessel production. The careful removal of each successive core enhances the successful completion of a vessel in brittle calcite, not to mention the harder stones in use by Egyptian artisans.
The experimental vase was now drilled to a depth of 3.5 cm with the 4 cm- and the 2.2 cm-diameter tubular drills . The cores were carefully removed with a mallet and a copper chisel. Pieces of the solid core were removed first, followed by the tubular core . The soft mallet blows were directed toward the centre of the vase. Other experimental work with the smaller tubular drills upon some sandstone and limestone specimens showed that the twist/ reverse twist forces, exerted upon a slim stone core by the finely ground sand powder trapped between the core and the drill's interior wall, caused it to fracture at its base. Care was taken to eliminate any lateral forces acting upon the core during these tests. The twist/reverse twist driven tube can also, very carefully, be forced to one side to snap off a slim core. The only other alternative is with a wedge. However, although this technique was employed for the drilling of sarcophagi (see Chapters 4 and 6), a wedge utilized to snap off a core in a vessel could break it. A broken calcite mortar (UC 16038) possibly suffered such a fate, although this mortar could have been drilled with a bow-driven tube; the core is tapered.
The vase now required undercutting at the shoulders, and then hollowing to follow its external shape. There are several ways that this could have been achieved in ancient times. First, tubular drill the vase completely to the bottom and then bore out the remainder of the stone with figure-of-eight-shaped stone borers . Second, tubular drill the vase to a point just below the shoulder and introduce a first figure-of-eight-shaped borer to force a sideways cut. This first borer would be slightly longer than the diameter of the tubular drill; the use of flint scrapers to scrape a slight groove in the wall of the hole would help in the introduction of this first figure-of-eight borer. Each successively longer figure-of-eight borer would further increase the undercutting to a point where downwards penetration became necessary. The tubular drilling and the core removal would recommence until the final depth was reached. However, flint scrapers and hand-held borers may have been used exclusively to undercut the shoulders before the first figure-of-eight borer was admitted. As the first short figure-of-eight borers deepened this initial undercut, successively longer and longer borers could be accommodated. This proposed technology follows the apparent initial techniques employed in the unfinished Liverpool Museum vase.
Third, tubular drill the vase to a point just below the shoulders, then use only successively larger figure-of-eight borers until the bottom is reached. This method is not supported by the striations seen on extant figure-of-eight borers, which are under the borers' extremities, not under their central parts. This indicates that such borers were always used to widen an existing hole. The second alternative was chosen for this particular vase, although methods need to be reviewed when taking into account other vessels' shapes and stones.
A groove was now scraped with a hand-held, hook-shaped flint scraper around the vase's internal circumference at a depth of 2 cm . A first figure-of-eight borer, slightly longer than the hole diameter of 4 cm, was slipped lengthways, that is, with its long axis vertical, into the hole, and brought to a nearly horizontal position . One end of the borer was located in the scraped groove. There is a difference with oblate, spheroidal-shaped vessels, where a vase's internal diameter is considerably larger than its height. A long figure-of-eight borer could not have been admitted vertically and turned to a horizontal position. However, the unusually large mouth size meant that a worker could admit a big hand-held borer, and this may have been the manner in which this type of vase was internally ground to shape.
The limestone vase was now filled with dry sand abrasive up to the level of the borer, and a forked shaft engaged with it. Gradual twist and reverse twist actions, together with a new grip every few twists, allowed the borer to settle into a fully horizontal position . The scraped groove was further cut sideways and downwards by these actions. The dry sand abrasive slowly eroded the vase interior, and also the borer. Occasionally, the sand powder was poured out of the vase, and fresh supplies admitted.
Ancient vases were probably held by friction in a socket hollowed into an earthen bench, or in the ground. Some earthen bench sockets have been found in an ancient vase grinder's workshop at Hierakonpolis by Quibell and Green, although their illustration shows a vase grinder in an earthen socket. All of the tomb representations depict stone vessels standing without support; conventions in tomb drawing may have ignored the true method of fastening vessels down for drilling and boring them.
Sometimes, craftworkers are shown steadying the vase with one hand. In the Twelfth Dynasty Tomb-Chapel of Ukh-hotp's son Senbi at Meir, one driller is saving to another worker: do you observe that this mnhw does not keep steady without its gum? The driller making the statement is holding a TRTD handle in the right hand, and the vase with the left hand. The worker is possibly suggesting that the stone vessel should be stuck down during the drilling work.
Tubular drilling continued to the bottom of the test vase, whereupon the cores were removed. Figure-of-eight borers finished the hollowing of the vase. A series of raised ridges, or cusps, were created as each successive borer ground away a groove into the vase's wall. These were smoothed away by long, hand-held sand­stone rubbers, the bottom being smoothed with a rounded stone borer, in use with sand abrasive. It is likely that an ancient stone vessel worker gathered many stone borers of different shapes and sizes over a lifetime's work. Just as a modern blacksmith keeps any special tool for possible future use, many borers in ancient tool collections would have been kept for such a purpose. The maximum internal diameter of the vase measured 8 cm, its minimum diameter being 5.5 cm, with a mouth diameter of 4.5 cm and a depth of 10 cm . The total time for manufacture was 22,4 hours.




Если есть вопросы - милости просим :)

ЗЫ.Что-то я у Стокса 2000-х годов не могу найти временных оценок по изготовлению для ваз из гранитов-диоритов в отличие от Стокса 80-90-х.